According to the association of fishing experts, elodea, an invasive species that is "on a large scale" in the Minho River, is completely blocking the shad and lamprey fishing nets, making it impossible for fishermen to operate as it becomes tangled in fishing nets. Despite being centred further upstream of the Minho River, the aquatic plant disrupts the entire riverbed through storms or currents.

Speaking to Lusa News agency, Augusto Porto from ‘Associação de Profissionais de Pesca do Rio Minho e Mar’ shared that this invasive species “is present in the Minho River on a very large scale. It greatly harms fishing activities, especially shad, lamprey or flounder. We were left with the nets completely covered, blocked”. As Augusto Porto added, “A fishing gear could work all day, but when we find these algae, we spend one, or two, or three [fishing gears], and we still can’t work,” he lamented, explaining that this invasive flora “looks like a current and entangles the entire network”.

Elodea is an invasive species that worries the biologist and environmentalist Ana Lages, who is part of ‘Corema’, a Non-Governmental Environmental Organization (ONGA) based in Caminha. As Ana Lages emphasised, “Elodeas are the most worrying aquatic invasive species in the Minho River, because they are really widespread and practically in all rivers and streams of Alto Minho”. Ana Lages clarifies that this plant “starts to grow, forms blankets and makes the rivers practically impassable”, in addition to making them unattractive to native fish species.

According to the biologist, there are measures which could be taken but they require a lot of money and a very carefully thought-out intervention that uses a lot of equipment and people. However, an alternative solution, as noted by Augusto Porto would be crushing the algae as they are doing in the Mondego River with another type of invasive species.